It’s easy to see why people lie to others: to keep their jobs, to avoid an argument with someone, to protect their reputation, or because they think everyone will be better off for it. It’s wrong, we know, but sometimes we figure that doing so is the best option in a sea of bad choices.

Lying to ourselves, though? It happens quite often, and as it turns out, we’re pretty good at it. We convince ourselves that we really need that new gadget, that we made a wise financial choice, or everything is fine (when it isn’t). Even if the evidence proves otherwise, we stick to our guns and refuse to back down.

More often than not, the lies we tell ourselves are harmful to our well-being and can be more damaging than we realize. So why do we do it?